Lubricant preparation



Patented May 21, 1940 LUBRICANT PREPARATION Robert E. Burk, Cleveland, Ohio, assignor to The I Standard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Application December 3, 1937. Serial No. 177,896

9 Claims.

In making lubricants particularly for high pressure usage, it is known practice to add to the oil foreign substances containing active elements such as sulphur, halogens, and the like. Prodnets on this order have a proclivity to deposit sediment, in some cases quite extensively. I believe that a fundamental aspect of the difficulty lies in the fact that the substances added are not sufliciently related to the oil. In accordance with 10 the present invention however, I am enabled to make up lubricants of excellent character, and having durable properties in usage and storage.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the ll features hereinafter fully described, and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a few of the various 20 ways in which the principle of the invention may be employed.

A petroleum hydrocarbon containing mercaptans, the organic sulphur compounds quite concomitant with petroleum, is treated to isolate g and further bring about addition of sulphur to the memaptan compounds, and the product is re-combined with the desired lubricant base. The mercaptan-containing petroleum for instance may be extracted with a sodium hydroxao ide solution, such as a two to twenty per cent solution, and the mercaptide thus formed may be then treated with sulphur, or conveniently a solution of sulphur in an organic solvent such as benzol or petroleum naphtha. In some cases de- 5 slrably, the caustic soda solution may then be contacted with lead sulphide or other sulphide catalysts. The sulphur compounds formed in the caustic solution are then dissolved therefrom by a suitable organic solvent, for instance a'petroleum naphtha. Or, in some cases, they may be separated from the caustic soda solution by suiliciently long settling or by centrifuging. The sulphur compounds may be accumulated further if desired by using a solvent over and over again 5 in solvent relation, and a high sulphur content may be obtained. Or a countercurrent extraction system may be used. The sulphur-containing compounds are taken from the organic solvent, for instance by distilling a lighter portion 50, of the hydrocarbon and leaving the sulphur-containing portion of the bottoms. Thus, employing naphtha as a collecting solvent for the sulphur compounds, on subjecting to distillation with steam, the material may be run down until the I u bottoms have an initial boiling point of m instance 475 F., and such bottoms may contain for example 40 to 50 per cent sulphur. This highly concentrated sulphur compound material derivedfrom petroleum is then incorporated with a desired lubricant oil, for instance a cylinder stock. 5 Generally, the amount of sulphur stock incorporated is such as to run the sulphur content of the product to 1-4 per cent.

Preparations on this order are particularly compatible with lead soaps, as for instance oil soluble lead naphthenates or other soap of petroleum-derived acids, which may be further incorporated. In general, where a lead compound is thus incorporated, the lead content calculated as lead oxide may range for instance 4 to 8 per cent.

As an example: A Mid-Continent bright stockhaving viscosity of 150 sec. at 210 F. Saybolt, and showing as Timken test 16# (at 800 R. P. M. 10 min., 5 min. run), is treated by incorporation of sulphur oil bottoms equivalent to 2% per cent 20 of added sulphur, the sulphur oil bottoms being prepared as above described.

As another example: With a similar lubricating stock of 150 viscosity at 210 F., there is incorporated a sulphurized oil bottoms as indicated,

and lead naphthenate the equivalent to 6 per cent PbO.

Generally, the oil base may be a bright stock, by preference, and of viscosity 90-160 S. U. at 210 F., but depending upon the particular usage in view, it may be any-stock desired. Thickening agents may be added, to form thicker lubricants, as greases. Thus, there may be incorporated polymer compounds, as for instance polyisobutylene, or there may be incorporated soaps of lead or calcium or sodium, or combinations of such thickening agents, the amount in each case depending upon the base stock selected, and the particular properties of the final grease desired.

The products of the present procedurehave very slight odor, if any, except that characteristic of the lubricating oil itself. Unlike some known lead-sulphur lubricants, the present products will not settle out deposits on standing, and they have a high film strength. Timken tests of 45 and are thus readily obtainable.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or 50 the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

1; A process of preparing lubricants, which comprises subjecting a mercaptan-containing hydrocarbon to the action of a solution consisting of water and 2 to 20 per cent caustic soda, treating the caustic soda solution with sulphur, extracting the caustic soda solution with a hydrocarbon solvent for the sulphur compounds, distilling ofl solvent from the extract, incorporating the sulphur-containing bottoms with a lubricating stock to a sulphur-content of 1-4 per cent, and incorporating an oil-soluble lead naphthenate to a lead content of 4-8 per cent calculated as PbO.

2. A process of preparing lubricants, which comprises subjecting a mercaptan-containing hydrocarbon to the action of a solution consisting of water and 2 to 20 per cent caustic soda, treating the caustic soda solution with sulphur, extracting the caustic soda solution with a hydrocarbon solvent for the sulphur compounds, distilling ofl solvent, and incorporating the sulphur-containing bottoms with a lubricating stock.

3. A process of preparing lubricants, which comprises subjecting a mercaptan-containing hydrocarbon to the action of a solution consisting of water and caustic soda, treating the caustic soda solution with sulphur, extracting the caustic soda solution with a selective solvent for the sulphur compounds, eliminating solvent, incorporating the sulphur-containing material 1 with a lubricating stock, and incorporating an hydrocarbon to the action of a solution consisting of water and 2 to 20 per cent caustic soda, treating the caustic soda solution with sulphur, segregating the sulphur compounds from such solution, and incorporating the sulphur compounds with a lubricating stock.

6. A process of preparing lubricants, which comprises subjecting a mercaptan-containing hydrocarbon to the action of a solution consisting of water and 2 to 20 per cent caustic soda, treating the caustic soda solution with sulphur, segregating the sulphur compounds from the solution, and incorporating the sulphur compounds and a lead soap with a lubricating oil.

7. A process of preparing lubricants, which comprises subjecting a mercaptan-containing hydrocarbon to the action of a solution consisting of water and 2 to 20 per cent caustic soda, treating the caustic soda solution with sulphur, segregating the sulphur compounds from the solution, and incorporating the sulphur compounds and a lead naphthenate with a lubricating oil.

8. A process of preparing lubricants, which comprises subjecting a mercaptan-containing hydrocarbon to the action of a solution consisting of water and 2 to 20 per cent caustic soda, treating the caustic soda. solution with sulphur, segregating the sulphur compounds from the solution, and incorporating the sulphur compounds and a lead soap of a petroleum-derived acid with a lubricating oil.

9; A new extreme pressure lubricant, comprising a lubricating oil and a concentrate of the product of reaction of mercaptan-containing hydrocarbon with a solution of caustic soda and with elemental sulfur according to the process set out in claim 4, said extreme pressure lubricant having slight odor, good stability against settling of deposits upon standing, and high film strength.

ROBERT E. BURK. 

